1. Field of the Invention
The novelty disclosed in this document pertains to hand tools. More narrowly, it applies to puller jaw positioning means for generic jaws typically incorporated with a slide hammer.
The generic slide hammer includes a yoke and jaw assembly, along with an element, the function of which is to force the jaws together or apart, depending on the orientation of the element. This element has a threaded cavity to allow it to attach to a threaded portion of a shaft that is incorporated in the slide hammer. One end of the element has a concave surface, while the opposing end has a convex surface. The orientation of the concave and convex surfaces on the assembly determine whether the jaws will be forced together or apart by the element.
This is where an opportunity for improvement lies with this assembly. This part, which I am referring to as the element, can merely press against one surface of each jaw. It is either forcing them together or apart, it can not restrict the travel of the jaws in the direction it is forcing the jaws. Additionally, in order to convert from one function to the other, the yoke and jaw assembly and the element must be removed from the threaded shaft so that the element can be flipped over and reinstalled.
The cam disclosed in this application: eliminates the need to dismantle the assembly in order to convert from one function to the other; it is used with the inexpensive generic jaws typical to slide hammers; it provides precise control of the inclination of the jaws; and it is an inexpensive improvement which offers significant time savings in set up.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Examining the patent record I did not find a record of a cam for controlling the positioning of puller jaws. I did find several pullers that include jaw positioning mechanisms and submit them here. Each of these pullers are commercially available.
While each of the prior art citations provide precise control of the jaw positions, they do not meet the criteria of: reversibility without disassembly; functionality with generic puller jaws typical to slide hammers; or small cost.
Prior Art Cited 5,174,005 Locking Puller Device Somerville 1992 5,224,254 Puller McPeak 1993 5,251,368 Internal Locking Puller Somerville 1993 5,557,833 Puller Device Pool 1996
Somerville's Locking Puller Device, U.S. Pat. No. 5,174,005, is a well designed puller for gripping externally and pushing internally. It's draw backs are: it can not be reconfigured to grip internally; and it is relatively expensive to manufacture.
McPeak's Puller, U.S. Pat. No. 5,224,254, is a versatile puller, which can grip internally or externally. The primary draw back of this device, as with all pullers with which I am acquainted, is that the adjusting component is a threaded rod. While a threaded rod provides the accuracy of adjustment and strength needed, it is an extremely slow adjustment method.
Somerville's Internal Locking Puller, U.S. Pat. No. 5,251,368, has the same drawbacks as his previously mentioned Locking Puller Device. The orientation of its' jaws are not reversible and it is expensive to manufacture.
Pool's Puller Device, U.S. Pat. No. 5,557,833, is a versatile puller, similar to McPeak's Puller. As with McPeak's Puller, the significant drawback is the use of a threaded rod for adjustment.